This invention relates to a process for the surface treatment of an aluminum article. More specifically, this invention relates to a process for the surface treatment of an aluminum article which has been anodically oxidized and which has a surface structure in an active state.
Conventionally, aluminum articles are generally subjected to an anodic oxidation in an electrolyte such as sulfuric acid, oxalic acid, chromic acid and the like in order to provide the aluminum articles with an anticorrosive property. The oxidized film formed on the aluminum articles by anodic oxidation comprises a porous .gamma.-Al.sub.2 O.sub.3 layer having a number of micro-pores having a diameter on the order of 100 to 500 .ANG., but such a layer is not sufficiently anticorrosive and, therefore, is generally subjected to hydrate sealing treatment in boiling water or pressurized steam or is coated with a resin over the anodically oxidized surface. The conventional methods for resin coating include spray coating of a solution or dispersion of a resin dissolved or suspended in water or an organic solvent; electrostatic coating by providing resin particles with electrostatic charge at the same time of spray coating; formation of a resin coating film by taking advantage of the viscosity of a resin solution and the volatility of a solvent, comprising dipping the article to be coated in a solution of resin dissolved or suspended in an organic solvent or water; formation of a resin film electrically comprising dipping an article to be coated in a solution of a water-soluble or water-dispersible resin and passing a D.C. or A. C. electric current between the electrodes provided in the solution; formation of a molten film of a resin by jet-spraying a resin powder toward the heated article to be coated or contacting the heated article with a fluidized resin powder, and the like.